Expansion joint fitting for flammable liquid

ABSTRACT

An expansion joint fitting for conveying liquid includes a radially inner bellows defining a liquid-conveying passage for conveying liquid between the first and second longitudinal ends of the expansion joint fitting. A radially outer bellows is disposed radially outward from and extending around the radially inner bellows. An annular plenum is defined between the radially inner bellows and the radially outer bellows.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a flanged fitting for asystem for flammable liquids. Such flanged fittings can include, but arenot limited to, equipment nozzle assemblies, piping, piping spools,valves, special fittings, covers, agitators, mechanical seals, baffles,and other flanged fittings.

BACKGROUND OF THE DISCLOSURE

The National Fire Protection Association's code NFPA 30 providessafeguards to reduce the hazards associated with the storage, handling,and use of flammable and combustible liquids. Suitable materials forflange fittings for flange joint assemblies for flammable andcombustible liquids under NFPA 30 may include carbon steel, nickelalloys and reactive metals, such as titanium, zirconium, and tantalum.Conventional glass-lined flanged fittings would not meet NFPA 30standard for flammable and combustible liquids or be able to pass thefire test specified in American Petroleum Institute API Specification6FB, “Specification for Fire Test for End Connections.”

One type of flanged fitting suitable for connection to a flanged conduitis an expansion joint fitting assembly. However, conventional expansionjoint fittings may not be suitable to meet NFPA 30 standard forflammable and combustible liquids when connected to non-metal linedequipment and/or may not pass the fire test specified in AmericanPetroleum Institute API Specification 6FB, “Specification for Fire Testfor End Connections.”

SUMMARY OF THE DISCLOSURE

In one non-limiting aspect, an expansion joint fitting for conveyingliquid, has first and second longitudinal ends and a longitudinal axisextending between the opposite first and second longitudinal ends. Theexpansion joint fitting generally comprises a radially inner bellowsdefining a liquid-conveying passage for conveying liquid between thefirst and second longitudinal ends of the expansion joint fitting. Aradially outer bellows is disposed radially outward from and extendingaround the radially inner bellows. An annular plenum is defined betweenthe radially inner bellows and the radially outer bellows.

In another non-limiting aspect, a flange joint assembly for conveyingliquid generally comprises an expansion joint fitting for conveyingliquid. The expansion joint fitting has first and second longitudinalends and a longitudinal axis extending between the opposite first andsecond longitudinal ends. The expansion joint fitting generallycomprises a bellows defining a liquid-conveying passage for conveyingliquid between the first and second longitudinal ends of the expansionjoint fitting. A first annular coupling flange at the first longitudinalend of the expansion joint fitting, and a second annular coupling flangeat the second longitudinal end of the expansion joint fitting. Thebellows is coupled to the first and second annular coupling flanges. Thebellows includes an annular corrugated body and opposite first andsecond longitudinal end portions secured to the respective first andsecond annular coupling flanges. Each of the first and secondlongitudinal end portions includes an annular radial segment secured toan axial end face of a corresponding one of the first and second annularcoupling flanges. The annular radial segment defines an annular gasketabutment face. An annular gasket includes an annular gasket layergenerally opposing and seated on the annular gasket abutment face. Theannular gasket layer includes a radially inner annular gasket segmentand a radially outer annular gasket segment surrounding the radiallyinner annular gasket segment. The radially inner annular gasket segmentcomprises a first material suitable for forming a liquid-tight seal withthe annular gasket abutment face. The radially outer annular gasketsegment comprises a second material suitable for forming a fire-ratedseal with the annular gasket abutment face.

Other features will be in part apparent and in part pointed outhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal section of one embodiment of a flange jointassembly constructed according to the teachings of the presentdisclosure;

FIG. 2 is an enlarged view as indicated in FIG. 1;

FIG. 3 is an enlarged view similar to FIG. 2, with an expansion jointfitting removed from the flange joint assembly, showing one embodimentof a flanged fitting of the flange joint assembly;

FIG. 4 is similar to FIG. 3, with an annular gasket removed from theflange joint assembly;

FIG. 5 is an elevational view of the annular gasket;

FIG. 6 is a cross section of the annular gasket taken in the planedefined by the line 6-6 in FIG. 5;

FIG. 7 is an enlarged, partial cross section of another embodiment of aflange joint assembly including two second embodiments of flangedfittings coupled to one another and the annular gasket disposedtherebetween;

FIG. 8 is an enlarged, partial cross section of one of the flangedfittings in FIG. 7;

FIG. 9 is a cross section of the expansion joint fitting constructedaccording to the teachings of the present disclosure; and

FIG. 10 is similar to FIG. 1 and additionally including a flangedliquid-conveying component attached to a downstream end of the expansionjoint fitting.

Corresponding reference characters indicate corresponding partsthroughout the drawings.

DETAILED DESCRIPTION OF THE DISCLOSURE

Referring to FIG. 1 of the drawings, a flange joint assembly suitablefor use in conveying flammable liquid, such as from a liquid-reactorand/or within liquid-conveying conduit system is generally indicated atreference numeral 10. In this illustrated embodiment, the flange jointassembly 10 comprises a flanged fitting, generally indicated at 12; anexpansion joint fitting, generally indicated at 14; an annular gasket,generally indicated at 15, disposed and sandwiched between the flangedfitting and the expansion joint fitting; and a flange coupler assembly,generally indicated at 16, coupling together the flanged fitting, theexpansion joint fitting and the annular gasket. It is understood thatflanged fitting 12 of the present disclosure may be used separate fromand independent of the illustrated expansion joint fitting 14 and/or theillustrated annular gasket 15; the expansion joint fitting 14 may beused separate from and independent of the illustrated flanged fitting 12and/or the illustrated annular gasket 15; and the annular gasket 15 maybe used separate and independent of the illustrated flanged fitting 12and/or the illustrated expansion joint fitting 14. For example, asexplained in more detail below, the flanged fitting 12 may be coupled toother types of conduits, other than the illustrated expansion jointfitting 14, including other types of expansion joint fittings, flangedpiping, flanged components, etc. (as represented schematically in FIG.3). The expansion joint fitting 14 may be coupled to other types offlanged fittings, other than the illustrated flanged fitting 12,including other types of nozzles, or piping, etc. The annular gasket 15may be coupled between other types of fittings, or piping, etc., otherthan the illustrated flanged fitting 12 and expansion joint fitting 14.

The flanged fitting 12 has a longitudinal axis LA1, opposite upstreamand downstream longitudinal ends (broadly, first and second longitudinalends), and a passage 20 extending longitudinally within the flangedfitting and through the upstream and downstream longitudinal endsthereof. As used herein when describing the flanged fitting 12 and itscomponents and structures, the longitudinal axis of the flanged fittingis used as the point of reference for the terms “axially,” “radially,”“inner,” “outer,” and like qualifiers. The illustrated flanged fitting12 is configured as a nozzle, such as a nozzle for a reactor vessel. Inother examples, the flanged fitting 12 may comprise other types offittings, including piping or other conduits for conveying liquids, orother types of fitting components, including covers, agitators,mechanical seals, baffles, valves, etc. for use in a liquid system.

The flanged fitting 12 comprises a conduit, generally indicated at 22,and an annular flange, generally indicated at 24, at a downstreamlongitudinal end of the flanged fitting. The conduit 22 comprises aconduit body 22 a (e.g., nozzle neck; pipe), and the annular flange 24comprises an annular flange body 24 a at a downstream longitudinal endof the conduit body. Together, the conduit body 22 a and the annularflange body 24 a form a fitting body of the flanged fitting 12. Thefitting body may be formed as a one-piece, monolithically formedcomponent, or the conduit body 22 a and the annular flange body 24 a maybe formed separately and secured to one another. The fitting body may befire-rated. As used herein, “fire-rated” means a component or structureis formed from material that meets the standard set forth in NFPA 30,and may include carbon steel, nickel alloys, reactive metals, andcombinations. The fitting body may be comprised of (e.g., be formedfrom) a metal material, such as carbon steel or other types of metal. Inthe illustrated embodiment shown in FIGS. 1-4, the fitting body may beformed as a suitable stub end for an ASME Class 150 or 300 joint flange.

An internal liner 26 lines an interior surface of the fitting body,including the conduit body 22 a and the annular flange body 24 a. In oneexample, the liner 26 acts as a corrosion-resistance barrier to inhibitliquid in the flanged fitting 12 from contacting and corroding thematerial (e.g., metal) of the fitting body. In one or more examples, theliner 26 may comprise (e.g., be formed from) a non-metal material, suchas glass, graphite, silicon carbide, ceramic, or other non-metalmaterial. In one example, the liner 26 may uniformly cover the entireinterior surfaces of the conduit body 22 a and the annular flange body24 a. The liner 26 may have a uniform thickness of up to about 100 mm orother thicknesses. As explained below, the fitting body is modified toensure the flange joint assembly 10 does not fail when subjected to afire test according to the API Specification 6FB, Titled “Specificationfor Fire Test for End Connections.” That is, the fitting body issuitable for passing the test set forth in API Specification 6FB.

For reasons explained below, as shown in FIGS. 2-4, the annular flange24 of the flanged fitting 12 also comprises an annular flange extension28 extending around the outer diameter portion of the annular flangebody 24 a and may be formed (e.g., forged and/or machined) as aone-piece, monolithically formed integral part of the annular flangebody 24 a. The annular flange extension 28 increases the diameter of theannular flange 24 of the flanged fitting 12 beyond standard ASME Class150 or 300 raised face dimensions without interfering with the flangedfitting 12 bolting 63 and fastener openings 56 and 220. The annularflange extension 28 may be fire-rated. For example, the annular flangeextension may be comprised of a (e.g., be formed from) a metal material,such as carbon steel or other types of metal that match the annularflange body 24 a. In one example, as shown in FIG. 4, the annular flangeextension 28 may have a radial width W1 of about ⅜″ (9.525 mm) toincrease the diameter of the annular flange 24 by ¾″ (1.905 cm). Inother embodiments, the annular flange extension 28 may be formedseparately and secured to the flange body 24 a of an ASME Class 150 or300 standard raised face configuration flanged fitting by welding or inother suitable ways.

The annular flange 24 of the flanged fitting 12 further comprises anannular insert or inlay 30 adjacent the outer radial end of the annularflange 24. The annular inlay 30 is positioned downstream of the annularflange extension 28 such that a radially outer annular portion of theannular inlay 30 overlies (as viewed from the downstream longitudinalend of the flanged fitting) and abuts the annular flange extension. Theannular inlay 30 may have an axial thickness T1 of about ¼″ (6.35 mm).Moreover, the radially outer surface of the annular inlay 30 isgenerally flush with the radially outer surface of the annular flangeextension 28. The annular inlay 30 extends radially inward relative tothe longitudinal axis LA1 of the flanged fitting 12 and into an annularrecess 34 of the annular flange body 24 a such that a radially outerannular portion of the liner 26 of the annular flange 24 overlies (asviewed from the downstream longitudinal end of the flanged fitting) andabuts a downstream surface of a radially inner annular portion of theannular inlay. In other words, the radially outer annular portion of theliner 26 of the annular flange 24 generally abuts and is positioneddownstream of the radially inner annular portion of the annular inlay30. The annular inlay 30 may be formed and secured from a welding method(i.e. weld overlay—thickness build-up through welding passes with finalmachining) to the annular flange body 24 a within the annular recess 34and forms a one-piece, monolithically formed annular flange body 24 a.In one example, as shown in FIG. 4, the annular inlay 30 may extendradially inward from the radially outer end of the liner 26 a distanced1, which may be about ¼″ (6.35 mm), to inhibit crevice corrosion thatcan propagate underneath the liner and lead to cracking and/or failureof the liner. In other embodiments, the annular inlay 30 may be formedseparately (e.g., forged and/or machined) and secured to the annularflange body 24 a within the annular recess 34 using a welding method orin other suitable ways.

The radially outer annular portion of the annular inlay 30 extends moreradially outward than the radially outer annular portion of the liner 26relative to the longitudinal axis LA1 of the flange fitting 12. Forexample, as shown in FIG. 4, the annular inlay 30 may extend radiallyoutward from the radially outer end of the liner 26 a distance d2, whichmay be about ⅜″ (9.525 mm). In the illustrated embodiment, the radiallyinner annular portion of the annular inlay 30 has an annular recess 36at its downstream longitudinal end surface in which the radially outerannular portion of the liner 26 is received such that the downstreamlongitudinal end surface of the annular inlay at its radially outerportion is generally flush with the downstream end surface of the linerat the radially outer portion of the liner. Thus, the glass liner 26lines a radially inner annular portion of the annular downstream endface of the annular fitting flange 24, and a radially outer annularportion of the annular downstream end face of the annular fitting flangeis free from the glass liner. Together, the downstream surface of theradially outer portion of the annular inlay 30 and the downstreamsurface of the liner 26 on the flange 24 define a gasket abutment faceat the downstream longitudinal end of the flanged fitting 12. Theannular gasket abutment face is generally planar and lies in a planegenerally perpendicular to the longitudinal axis LA1 of the flangedfitting 12. The downstream longitudinal surface of the radially outerannular portion of the annular inlay 30 partially defining the gasketabutment face may include a roughened finish, e.g., a spiral serratedfinish (broadly, a serrated surface), to enhance and/or facilitateseating of the annular gasket 15 on the gasket abutment surface. Forexample, the downstream surface of the radially outer annular portion ofthe annular inlay 30 may include a spiral serrated finish of about 125to about 250 root mean square (RMS) micro inches.

For reasons explained below, the annular inlay 30 may be fire-rated. Forexample, the annular inlay 30 may comprise (e.g., be formed from) metal,such as a nickel alloy (e.g., Alloy 625, Alloy 600, AlloyC-276/C-22/C-2000, Hastelloy® G-30/G-35/BC-1, Inconel® 686, Monel® 400,Alloy 825, Alloy 200, AL-6XN®, or 904L SS, Alloy 20), a reactive metal(e.g., titanium Gr. 2/Gr. 7, zirconium 702, tantalum, tantalum with 2.5%tungsten), a stainless or duplex stainless steel, or combinationsthereof, including alloys thereof. In one example, the annular inlay 30is formed from Alloy 625.

In one method of making the flanged fitting 12, a one piece,monolithically formed flanged fitting including the annular flangeextension is provided (e.g., forged and/or machined) as the fittingbody. The fitting body is machined to form the annular recess 34 in thebody. The annular inlay 30 is formed and secured from a welding method(e.g., weld overlay—thickness build-up through welding passes with finalmachining) to the annular flange body 24 a within the annular recess 34and forms a one-piece, monolithically formed annular flange body 24 a.The recess 36 of the inlay 30 is machined. The liner 26 (e.g., glass) isthen applied to the interior surface of the flanged fitting body. Theflanged fitting 12 may be formed in other suitable ways where theannular flange extension 28 and the annular inlay 30 are formedseparately or a combination of monolithically formed parts and separatecomponents and secured using a welding method or in other suitable ways.

Referring to FIGS. 5 and 6, the annular gasket 15 comprises opposingfirst and second annular gasket layers, generally indicated at 40 a, 40b, respectively, (e.g., longitudinally upstream and downstream annulargasket layers), and an inner annular substrate 42 sandwiched between thefirst and second annular gasket layers. As used herein when describingthe annular gasket 15 and its components and structures, an axis Al ofthe annular gasket is used as the point of reference for the terms“axially,” “radially,” “inner,” “outer,” and like qualifiers. Eachannular gasket layer 40 a, 40 b comprises a radially inner annulargasket segment 44 and a radially outer annular gasket segment 46 securedto a radially outer end of and circumferentially surrounding theradially inner annular gasket segment.

The radially inner annular gasket segment 44 of the upstream annulargasket layer 40 a generally opposes, abuts and seats against the liner26 of the annular flange 24. The radially inner annular gasket segment44 of the downstream gasket layer 40 b is configured to generallyoppose, abut and seat against an annular flange or other component ofthe other component (e.g., the expansion joint fitting 14) of the flangejoint assembly 10. The radially inner annular gasket segment 44 is sizedand shaped to extend from the radially outer end of the liner 26 on theannular flange 24 toward longitudinal axis of the flanged fitting 12when the joint flange assembly 10 is assembled. In one example, theradially outer ends of the radially inner annular gasket segments 44 andthe radially outer end of the liner 26 of the annular flange 24 arespaced at an equal radial distance from the longitudinal axis LA1 of theflanged fitting 12 such that the two radially outer ends are generallyaligned axially. The radially inner annular gasket segment 44 of theupstream annular gasket layer 40 a accommodates imperfections in theliner 26, provides a chemical seal, and protects and inhibits breakageof the non-metal liner, which may be glass or other frangible material.The radially inner annular gasket segments 44 of the upstream anddownstream annular gasket layers 40 a, 40 b may comprise (e.g., beformed from) a fluoropolymer, such as polytetrafluoroethylene (PTFE),including expanded PTFE (ePTFE). An example of suitable ePTFE is soldunder the trademark GORE® GR and manufactured by W. L. Gore &Associates. The radially inner annular gasket segments 44 of theupstream and downstream layers 40 a, 40 b may comprise (e.g., be formedfrom) other types of materials, including other types of polymers.Together, the radially inner annular gasket segment 44 of the upstreamannular gasket layer 40 a and the liner 26 (e.g., glass liner) of theannular flange 24 form a liquid-tight seal.

The radially outer annular gasket segment 46 of the upstream annulargasket layer 40 a generally opposes, abuts and seats against the annularinlay 30 of the annular flange 24. The radially outer annular gasketsegment 46 of the downstream annular gasket layer 40 b is configured togenerally oppose, abut and seat against an annular flange or othercomponent of the other component (e.g., the expansion joint fitting 14)of the flange joint assembly 10. The radially outer annular gasketsegment 46 is sized and shaped to radially extend from the radiallyouter end of the annular inlay 30 on the annular flange 24 toward thelongitudinal axis LA1 of the flanged fitting 12 when the joint flangeassembly 10 is assembled. In one example, the radially outer ends of theradially outer annular gasket segments 46 are generally flush with theradially outer end of the annular inlay 30. The spiral serrated finishof the downstream surface of the radially outer annular portion of theannular inlay 30 facilitates seating of the radially outer annulargasket segment 46 of the upstream gasket layer 40 a on the annular inlayand inhibits movement of the gasket 15 relative to the annular inlay andthe flanged fitting 12. The layers 40 a, 40 b of the radially outergasket segment 46 provide a fire-rated seal at the outer radial end ofthe annular flange 24. The radially outer annular gasket segments 46 ofthe upstream and downstream layers 40 a, 40 b may comprise (e.g., beformed from) graphite, such as flexible graphite. The radially outerannular gasket segments 46 of the upstream and downstream layers 40 a,40 b may be fire-rated. An example of a suitable radially outer annulargasket segment 46 of flexible graphite is sold under the trademarkGRAFOIL® gasket and manufactured by GrafTech International. The radiallyouter annular gasket segments 46 may comprise (e.g., be formed from)other types of materials, including other types of fire-rated materials.Together, the radially outer annular gasket segment 46 of the upstreamgasket layer 40 a and the annular inlay 30 of the annular flange 24 forma fire-rated seal.

The inner annular substrate 42 of the annular gasket 15 extends along anentire radial width of the gasket from the inner radial end to the outerradial end thereof. The annular substrate is provided for blow-outresistance to inhibit the annular gasket layers 40 a, 40 b from beingunseated radially and/or forced radially out of its position between theannular flange 24 and the second conduit (e.g., the expansion jointfitting). In the illustrated embodiment, the annular substrate 42 iscorrugated radially along its radial width to enhance friction betweenthe annular substrate the annular gasket layers 40 a, 40 b. The annularsubstrate 42 may be fire-rated. For example, the annular substrate 42may comprise (e.g., be formed from) metal, such as, a nickel alloy(e.g., Alloy 625, Alloy 600, Alloy C-276/C-22/C-2000, Hastelloy®G-30/G-35/BC-1, Inconel® 686, Monel® 400, Alloy 825, Alloy 200, AL-6XN®,or 904L SS, Alloy 20), a reactive metal (e.g., titanium Gr. 2/Gr. 7,zirconium 702, tantalum, tantalum with 2.5% tungsten), a stainless orduplex stainless steel, or combinations thereof, including alloysthereof. In one example, the annular substrate 42 is formed fromtantalum. The annular substrate 42 may comprise (e.g., be formed from)other types of materials, including other types of fire-rated materials.

In the illustrated embodiment, as shown in FIG. 6, a combined,uncompressed axial thickness T2 of the gasket layers 40 a, 40 b and theannular substrate 42 at the radially inner annular gasket segment 44 isgreater than the combined, uncompressed axial thickness T3 of the layersand the annular substrate 42 at the radially outer annular gasketsegment 46. When sandwiched between the flanged fitting 12 and thesecond flanged conduit (e.g., expansion joint fitting 14), such as shownin FIG. 3, the axial thickness of the gasket 15 may be substantiallyuniform along the radial width. As such, the gasket layers 40 a, 40 b atthe radially inner annular gasket segment 44 (e.g., ePTFE layers) arecompressed more than the gasket layers at the radially outer annulargasket segment 46 (e.g., flexible graphite layers). Such a configurationmay be advantageous where the layers 40 a, 40 b at the radially innerannular gasket segment 44 (e.g., ePTFE layers) need to be compressedmore than the gasket layers at the radially outer annular gasket segment46 (e.g., flexible graphite layers) to provide a suitable seal with theliner 26 at the annular flange 24.

As explained above, the flange coupler assembly 16 is used to couple theflanged fitting 12 and the annular gasket 15 to a second conduit, e.g.,the expansion joint fitting 14. In the illustrated embodiment, theflange coupler assembly 16 comprises an annular coupling flange 50(e.g., a split flange or lap flange) configured to engage a upstream endsurface of the annular flange of the flanged fitting 12. As used hereinwhen describing the first annular coupling flange 50 and its componentsand structures, an axis A2 of the flange coupler assembly is used as thepoint of reference for the terms “axially,” “radially,” “inner,”“outer,” and like qualifiers. A downstream face of the first annularcoupling flange 50 defines an annular flange recess 52 at a radiallyinner portion thereof extending around the axis A2 of the flange couplerassembly 16 in which a portion of the annular flange 24 of the flangedfitting 12, including a portion of the radially outer end thereof, isreceived. The annular coupling flange 50 defines a plurality of fasteneropenings 56 spaced apart around the axis A2 of the flange couplerassembly 16 and extending through the upstream and downstream faces ofthe first annular coupling flange. The fastener openings 56 are axiallyalignable with fastener openings in an opposing annular coupling flange,for example. (The illustrated opposing annular coupling flange isdiscussed in more detail below when discussing the expansion jointfitting 14.) The first annular coupling flange 50 may comprise (e.g., beformed from) a metal material, such a carbon steel or other types ofmetal. The flange coupler assembly 16 suitably facilitates aliquid-tight and fire-rated seal at the gasket 15 interfaces and doesnot exceed compressive force that would crush the gasket layers 40 a, 40b and/or crack the liner 26 (e.g., glass liner).

The gasket 15 ensures the flange joint assembly 10 does not fail whensubjected to a fire test temperature between 1400° F.-1800° F. (761°C.-980° C.) for a period of 30 minutes, according to the APISpecification 6FB, Titled “Specification for Fire Test for EndConnections.” That is, the gasket 15 is suitable for passing the testset forth in API Specification 6FB. The radially outer annular gasketsegment 46 and the annular inlay 30 form an annular fire-rated seal toinhibit spreading of fire from outside the flange joint assembly 10 tothe inside, and from inside the flange joint assembly to outside due toone or more of spalling and/or melting of the liner 26 (e.g., glassliner) and/or melting of the radially inner annular gasket segment 44(e.g., ePTFE material) of the annular gasket 15. This fire-rated seal isdue to each of the radially outer annular gasket segments 46, theannular substrate 42, and the annular inlay 30, which are fire-rated,being radially outward of the radially inner annular gasket segment 44and the liner 26 (e.g., glass liner), each of which are not formed frommaterial meeting NFPA 30. In one embodiment, where the annular inlay 30is a nickel alloy (e.g. Alloy 625) or reactive metal, the inlay has hightemperature capability to reduce sensitization of the inlay 30 in aglass furnace when applying the glass liner 26, for example, so thatcorrosion resistance is not reduced. High corrosion resistance mayreduce corrosion of the fire-rated seal, such as during maintenance ofthe flange joint assembly 10. The inlay 30 may be of other materials.

In addition to forming a fire-rated seal, the annular gasket 15 createsa liquid-tight seal at the interface of the liner 26 (e.g., glass liner)and the radially inner annular gasket segment 44 (e.g., ePTFE).Moreover, the annular insert 30 provides blow-out resistance to inhibitthe gasket 15 from being displaced from between the flange jointassembly 10 (e.g., unseated) if pressure rises within the flange jointassembly, such as due to an internal fire. In one particular embodiment,the annular insert also maintains the fire rating of the fire-rated sealat the radially outer annular gasket segment 46 and maintains the firerating of the gasket 15 as a whole. For example, the annular insert 30may be fire-rated. For example, the annular insert 30 may comprise(e.g., be formed from) metal, such as nickel alloy, reactive metal. Inone or more embodiments, the radially outer annular gasket segment 46also eliminates electrical grounding issues and development of staticbuild-up where each of the layers 40 a, 40 b and the annular substrate42 at the radially outer annular gasket segments 46 are electricallyconductive. This arrangement will dissipate any static charge orelectrical energy from equipment to the conduit system without the needfor electrical jumpers which is a specific requirement in NFPA 30,Section 6.5.4, Titled “Static Electricity.”

The flanged fitting 10, including the annular gasket 15, may be coupledto another component (e.g., liquid-conveying component) having a flangedesign suitable for the joint assembly to pass the test in APISpecification 6FB. In addition to the illustrated expansion jointfitting 14, described below, non-limiting examples of flange designssuitable for components to be coupled with the flanged fitting,including the annular gasket 15, include, but are not limited to: 1)flat faced metallic weld-neck or slip-on flange with spiral serratedfinish across the special raised face diameter equal to the diameter ofthe annular flange 24 of the flanged fitting 10; 2) lap joint flangewith metallic stub-end raised face diameter equal to diameter of theannular flange 24 of the flanged fitting 10; 3) metal lined (e.g.,tantalum) flange with metal liner raised face diameter equal to diameterof the annular flange 24 of the flanged fitting 10; and 4) glass-linedcarbon steel flange similar or identical to the annular flange of theflanged fitting 10. The components for coupling with the flanged fitting10 may have other flange designs.

Referring to FIG. 7, another embodiment of a flange joint assembly isgenerally indicated at 110. This flange joint assembly 110 is thesimilar to the first flange joint assembly 10, with differences betweendescribed hereinafter. Identical components are indicated by the samereference numbers.

Unlike the first flange joint assembly 10, the present flange jointassembly 110 includes flanged fittings 112 that are suitable for beingcoupled together or to other fittings using a flange clamp(s) 168 ratherthan a coupling flange component, as with the first embodiment. To thisend, an annular flange extension 128 of the flanged fitting 112 has arounded end 170 that project axially from the annular flange body 24 a.The rounded upstream end 170 accommodates the flange clamp(s). As anexample, the flanged fittings 112 may be used as or incorporated on oneor more of manways, dome covers, nozzles, nozzle covers, piping, othertrim/equipment connections, etc. The flanged fittings 112 may bemanufactured in substantially the same way as the first flange fitting12.

Referring to FIGS. 1 and 9, the illustrated expansion joint fitting 14defines a liquid flow passage 208 extending along a longitudinal axisLA2 of the expansion joint fitting. The expansion joint fitting 14comprises first and second annular coupling flanges 210, 212,respectively, (e.g., upstream and downstream coupling flanges) spacedapart from one another along the longitudinal axis LA2 of the expansionjoint fitting; and concentric radially inner and outer bellows,generally indicated at 216, 218, respectively, extending axially betweenand interconnecting the upstream and downstream coupling flanges. Asused herein when describing the expansion joint fitting 14 and itscomponents and structures, the longitudinal axis LA2 of the expansionjoint fitting is used as the point of reference for the terms “axially,”“radially,” “inner,” “outer,” and like qualifiers. The radially innerand outer bellows 216, 218 are radially spaced apart from one another todefine an annular plenum 219 therebetween extending axially along theexpansion joint fitting 14.

Each of the upstream and downstream annular coupling flanges 210, 212defines a plurality of fastener openings 220 spaced apart around thelongitudinal axis LA2 of the expansion joint fitting 14 and extendingthrough the upstream and downstream faces of the corresponding annularcoupling flange. The fastener openings 220 are axially alignable withfastener openings (e.g., openings 56, FIG. 2) in an opposing annularcoupling flange (e.g., coupling flange 50), as shown in FIG. 1, forexample. Each of the annular coupling flanges 210, 212 may comprise(e.g., be formed from) a metal material, such a carbon steel or othertypes of metal. For reasons explained below, in the illustratedembodiment (FIG. 9) a radial width W2 of one or more of the annularcoupling flanges 210, 212 may be greater than a radial width of theannular coupling flange 50 of the illustrated flanged fitting 12.

The radially inner bellows 216 includes an annular corrugated body 224and opposite upstream and downstream longitudinal end portionsrespectively, secured to the respective upstream and downstream annularcoupling flanges 210, 212, respectively. The upstream longitudinal endportion of the radially inner bellows 216 includes an axial segment 226a extending along and secured to the interior annular surface of theupstream coupling flange 210, and an annular radial segment 228 aextending radially outward from the axial segment radially along andsecured to a upstream end face of the upstream annular coupling flange210. The downstream longitudinal end portion of the radially innerbellows 216 includes an axial segment 226 b extending along and securedto the interior annular surface of the downstream coupling flange 212,and an annular radial segment 228 b extending radially outward from theaxial segment radially along and secured to a downstream end face of thedownstream annular coupling flange 212. The annular radial segments 228a, 228 b define respective first and second annular gasket abutmentfaces of the expansion joint 14.

The radially inner bellows 216 may be fire-rated. The radially innerbellows 216 may comprise (e.g., be formed from), metal such as nickelalloy (e.g., Alloy 625, Alloy 600, Alloy C-276/C-22/C-2000, Hastelloy®G-30/G-35/BC-1, Inconel® 686, Monel® 400, Alloy 825, Alloy 200, AL-6XN®,or 904L SS, Alloy 20), a reactive metal (e.g., titanium Gr. 2/Gr. 7,zirconium 702, tantalum, tantalum with 2.5% tungsten), a stainless orduplex stainless steel, or combinations thereof, including alloysthereof. In one example, the radially inner bellows 216 ismulti-layered. For example, the radially inner bellows 216 may include aradially innermost layer comprising a first type of material (e.g., areactive metal or nickel alloy), and one or more radially outer layers,each comprising a material different from the innermost layer (e.g., areactive metal or nickel alloy). In one example, the radially innermostlayer of the radially inner bellows 216, which defines theliquid-conveying passage 208 of the expansion joint fitting, maycomprise tantalum, or another type of reactive metal. In this sameexample, the one or more radially outer layers (e.g., two, three, ormore layers) may comprise Alloy 625, or another type of nickel alloy.Each of the layers of the radially inner bellows 216 may have athickness of about 0.5 mm. The respective downstream and upstreamlongitudinal end portions of the radially inner bellows 216 may besecured to the corresponding annular coupling flanges 210, 212, such asby spot welding, seal welding, or in other ways.

The radially outer bellows 218 includes a corrugated body and is coupledto the upstream and downstream annular coupling flanges 210, 212 bycorresponding upstream and downstream annular mounting brackets 234,236, respectively, mounted on the respective upstream and downstreamannular coupling flanges. The upstream annular mounting bracket 234 onthe upstream annular coupling flange 210 is disposed radially outward ofthe radially inner bellows 216 and projects axially (i.e., downstream)toward the downstream annular coupling flange 212. The downstreamannular mounting bracket 236 on the downstream annular coupling flange212 is disposed radially outward of the radially inner bellows 216 andprojects axially (i.e., upstream) toward the upstream annular couplingflange 210. The annular mounting brackets 234, 236 may be welded to thecorresponding upstream and downstream annular coupling flanges 210, 212,or may be secured thereto in other ways. In one example, thicknesses ofthe annular mounting brackets 234, 236 may taper along their axiallengths in a direction away from the respective adjoining annularcoupling flanges 210, 212 to accommodate outer bellows having increaseddiameters.

The radially outer bellows 218 may be fire-rated and may comprise (e.g.,be formed from) metal, such as, but not limited to, nickel alloy (e.g.,Alloy 625, Alloy 600, Alloy C-276/C-22/C-2000, Hastelloy®G-30/G-35/BC-1, Inconel® 686, Monel® 400, Alloy 825, Alloy 200, AL-6XN®,or 904L SS, Alloy 20), a reactive metal (e.g., titanium Gr. 2/Gr. 7,zirconium 702, tantalum, tantalum with 2.5% tungsten), a stainless orduplex stainless steel, or combinations thereof, including alloysthereof. In one example, the radially outer bellows 218 ismulti-layered. For example, each of the layers of the radially outerbellows 218 may comprise (e.g., be formed from) nickel alloy, such asAlloy 625, or another type of nickel alloy. Each of the layers of theradially outer bellows 218 may have a thickness of about 0.5 mm. Therespective downstream and upstream longitudinal end portions of theradially outer bellows 218 may be secured to the corresponding annularmounting brackets 234, 236, such as by welding or in other ways.

The expansion joint fitting 14 further includes an inlet port 244 and anoutlet port 246, each of which is in fluid communication with theannular plenum 219. As shown in the illustrated embodiment, the inletport 244 may be mounted on the downstream annular mounting bracket 236and/or the downstream annular coupling flange 212 radial surface andextend radially outward therefrom, and the outlet port 246 may bemounted on the upstream annular mounting bracket 234 and/or the upstreamannular coupling flange 210 radial surface and extend radially outwardtherefrom. It is understood that the locations of the ports 244, 246 maybe reversed in other embodiments. The inlet port 244 mounted on thedownstream annular mounting bracket 236 is in fluid communication withthe annular plenum 219 via an opening in the downstream annular mountingbracket. The inlet port 244 mounted on the downstream annular couplingflange 212 radial surface is in fluid communication with the annularplenum 219 via a passage 248 through the downstream annular couplingflange 212. In one example, the passage 248 may include a radial portioncentered between fastener openings 220 and an axial portion with directentry into the annular plenum 219. The outlet port 246 mounted on theupstream annular mounting bracket 234 is in fluid communication with theannular plenum 219 via an opening in the upstream annular mountingbracket. The outlet port 246 is mounted on the upstream annular couplingflange 210 radial surface is in fluid communication with the annularplenum 219 via a passage 249 through the upstream annular couplingflange 210. In one example, the passage may include a radial portioncentered between fastener openings 220 and an axial portion with directentry into the annular plenum 219. In one example, the inlet and outletsports 244, 246 may be of an ASME Class 150 or 300 standard raised faceconfiguration fitting secured by welding or in other suitable ways. Itis understood that the inlet and outlet ports 244, 246 may beconstructed from other suitable fitting types such as threaded,buttwelded, socket-welded, compression fittings, etc. in otherembodiments.

In use, a purge gas (e.g., an inert gas, such as, but not limited to,nitrogen) from a gas source 250 is delivered into the annular plenum219. The gas source 250 may include a compressor or gas cylinder forpressurizing the gas. The purge gas flows axially (e.g., upstream)through the annular plenum 219 and exits the annular plenum through theoutlet port 246. In the illustrated embodiment, the axial flow of purgegas (as indicated by arrows G) through the annular plenum 219 is in anaxial direction (e.g., upstream) that is opposite the axial direction(e.g., downstream) of the flow of liquid through the expansion jointfitting 14 (as indicated by arrows labeled L). In other embodiments, theaxial flow of purge gas may be in the same direction as the flow ofliquid.

In one embodiment, the purged gas that has exited the annular plenum 219may be analyzed to determine if liquid in the expansion joint fitting 14is leaking through the radially inner bellows 216, which may indicatefailure of the expansion joint fitting. In particular, if liquid or gas(i.e., fluid) is leaking into the annular plenum 219, at least someamount of the liquid or gas will be entrained in the flowing purge gasand carried outside the annular plenum through the outlet port 246. Theexited purge gas may be analyzed continuously or periodically to detectany potential failure of the expansion joint fitting 14. For example,the exited purge gas may flow through a detector or analyzer 254suitable for detecting the flammable liquid or gas or other foreignsubstances entrained in the purge gas. The purge gas may be in a closedloop system, whereby any foreign substance in the purge gas is filteredvia a filter system before being re-delivered into the annular plenum219.

In one embodiment, one or more leak detection openings 260 are formed inthe radially inner bellows 216 adjacent the inlet port 244 when theinner bellows 216 is multi-layered. The leak detection openings 260penetrate only the outer layers of the inner bellows 216 in this exampleand fluidly connect the liquid flow passage 208 to the annular plenum219 so that leak detection can be more expedient due to failure of theinner layer of the inner bellows 216 which can be a different materialof construction (MOC) from the outer layers of the inner bellows 216.This will provide a leak detection alert that there is a corrosion orfailure issue with the inner layer of the multi-layer inner bellows 216.In one example, one or more leak detection openings may have a diameterof about 3 mm.

In the illustrated embodiment, the expansion joint fitting 14 is coupledto the flanged fitting 12 and the gasket 15 so that the joint assembly10 is liquid-tight and passes the test set forth in API Specification6FB. In this example, the annular coupling flange 50 of the flangedfitting 12 is secured to the upstream annular coupling flange 210 of theexpansion joint fitting 14 with the fasteners extending through thecorresponding aligned fastener openings 56, 220. As coupled, thedownstream face of the gasket 15 abuts and seats on an upstream face ofthe annular radial segment 228 a of the radially inner bellows 216 toform a liquid-tight and fire-rated seal. In particular, the annularradial segment 228 a abuts and seats on both the radially outer annulargasket segment 46 to form the fire-rated seal, and the radially innerannular gasket segment 44 to form the liquid-tight seal.

The illustrated expansion joint fitting 14 provides secondary protectionshould a leak form in the radially inner bellows 216. That is, radiallyouter bellows 218 provides a secondary barrier so that any liquid or gas(i.e., fluid) leaking into the annular plenum 219 is contained thereinto inhibit leaking of the liquid or gas externally of the expansionjoint fitting 14. As also set forth above, the expansion joint fitting14 may facilitate leak detection of liquid or gas leaking into theannular plenum. Liquid or gas in the annular plenum 219 may be entrainedin the purge gas flowing through the annular plenum. This liquid or gasmay be detected by the detector or analyzer 254 to indicate thepossibility of a leak. Moreover, the purge gas may facilitate removal ofthe leaked liquid or gas from the annular plenum 219 to further inhibitany leaking of liquid or gas outside the expansion joint fitting 14.

The expansion joint fitting 14, including the annular gasket 15, may becoupled to another component (e.g., liquid-conveying component) having aflange design so that the joint assembly passes the test in APISpecification 6FB. In addition to the illustrated flanged fitting 10,described below, non-limiting examples of flange designs suitable forcomponents to be coupled with the expansion joint fitting 14, includingthe annular gasket 15, include, but are not limited to: 1) flat facedmetallic weld-neck or slip-on flange with spiral serrated finish acrossthe special raised face diameter equal to one or both of the diametersof the annular radial segments 228 a, 228 b of the inner bellows 216 ofthe expansion joint fitting 14; 2) lap joint flange with metallicstub-end raised face diameter equal to one or both of the diameters ofthe annular radial segments 228 a, 228 b of the inner bellows 216 of theexpansion joint fitting 14; 3) metal lined (e.g., tantalum) flange withmetal liner raised face diameter equal to one or both of the diametersof the annular radial segments 228 a, 228 b of the inner bellows 216 ofthe expansion joint fitting 14, such as flange 310 with metal liner 326(e.g., tantalum) illustrated in FIGS. 10; and 4) glass-lined carbonsteel flange similar or identical to the annular flange of the flangedfitting 10. The components for coupling with the expansion joint fitting14 may have other flange designs.

Modifications and variations of the disclosed embodiments are possiblewithout departing from the scope of the invention defined in theappended claims.

When introducing elements of the present invention or the embodiment(s)thereof, the articles “a”, “an”, “the” and “said” are intended to meanthat there are one or more of the elements. The terms “comprising”,“including” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements.

As various changes could be made in the above constructions, products,and methods without departing from the scope of the invention, it isintended that all matter contained in the above description and shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:
 1. An expansion joint fitting for conveying liquid,the expansion joint fitting having first and second longitudinal endsand a longitudinal axis extending between the opposite first and secondlongitudinal ends, the expansion joint fitting comprising: a radiallyinner bellows defining a liquid-conveying passage for conveying liquidbetween the first and second longitudinal ends of the expansion jointfitting; a radially outer bellows disposed radially outward from andextending around the radially inner bellows, wherein an annular plenumis defined between the radially inner bellows and the radially outerbellows.
 2. The expansion joint fitting set forth in claim 1, furthercomprising a first annular coupling flange at the first longitudinal endof the expansion joint fitting, and a second annular coupling flange atthe second longitudinal end of the expansion joint fitting, wherein theradially inner and radially outer bellows are coupled to the first andsecond annular coupling flanges.
 3. The expansion joint fitting setforth in claim 2, wherein the radially inner bellows includes an annularcorrugated body and opposite first and second longitudinal end portionssecured to the respective first and second annular coupling flanges,wherein each of the first and second longitudinal end portions includesan annular radial segment secured to an axial end face of acorresponding one of the first and second annular coupling flange. 4.The expansion joint fitting set forth in claim 3, further comprising: afirst annular mounting bracket extending outward from the first annularcoupling flange toward the second annular coupling flange, wherein thefirst annular mounting bracket extends around a portion of the radiallyinner bellows; and a second annular mounting bracket extending outwardfrom the second annular coupling flange toward the first annularcoupling flange, wherein the second annular mounting bracket extendsaround a portion of the radially inner bellows, wherein the radiallyouter bellows is secured to and extends between the first and secondannular mounting brackets.
 5. The expansion joint fitting set forth inclaim 4, further comprising: an inlet port secured to at least one ofthe first annular mounting bracket and the first annular coupling flangeand in fluid communication with the annular plenum; and an outlet portsecured to at least one of the second annular mounting bracket and thesecond annular coupling flange and in fluid communication with theannular plenum.
 6. The expansion joint fitting set forth in claim 5,further comprising a source of purge gas fluidly connected to the inletport, wherein the source of purge gas is configured to deliver purge gasinto the annular plenum through the inlet port.
 7. The expansion jointfitting set forth in claim 6, further comprising a fluid detectorfluidly connected to the outlet port to receive purge gas exiting theoutlet port, wherein the fluid detector is configured to detect fluidentrained in the purge gas that has leaked into the annular plenum. 8.The expansion joint fitting set forth in claim 7, wherein the radiallyinner bellows comprises one or more of a nickel alloy and a reactivemetal.
 9. The expansion joint fitting set forth in claim 7, wherein theradially inner bellows comprises a plurality of layers, wherein aninnermost layer of the radially inner bellow comprises one or more oftitanium, zirconium, tantalum.
 10. The expansion joint fitting set forthin claim 9, wherein the radially outer bellows comprises one or morelayers of a nickel alloy.
 11. The expansion joint fitting set forth inclaim 1, wherein the radially inner bellows comprises one or more of anickel alloy and a reactive metal.
 12. The expansion joint fitting setforth in claim 11, wherein the radially inner bellows comprises aplurality of layers, wherein an innermost layer of the radially innerbellow comprises one or more of titanium, zirconium, tantalum.
 13. Theexpansion joint fitting set forth in claim 12, wherein other layers ofthe plurality of layers of the radially inner bellows comprises a nickelalloy.
 14. The expansion joint fitting set forth in claim 12, whereinthe radially outer bellows comprises a nickel alloy.
 15. The expansionjoint fitting set forth in claim 14, wherein the radially outer bellowscomprises a plurality of layers, wherein each of the plurality of layerscomprises a nickel alloy.
 16. A flange joint assembly for conveyingliquid, the flange joint assembly comprising: an expansion joint fittingfor conveying liquid, the expansion joint fitting having first andsecond longitudinal ends and a longitudinal axis extending between theopposite first and second longitudinal ends, the expansion joint fittingcomprising: a bellows defining a liquid-conveying passage for conveyingliquid between the first and second longitudinal ends of the expansionjoint fitting; a first annular coupling flange at the first longitudinalend of the expansion joint fitting, and a second annular coupling flangeat the second longitudinal end of the expansion joint fitting, whereinthe bellows is coupled to the first and second annular coupling flanges,wherein the bellows includes an annular corrugated body and oppositefirst and second longitudinal end portions secured to the respectivefirst and second annular coupling flanges, wherein each of the first andsecond longitudinal end portions includes an annular radial segmentsecured to an axial end face of a corresponding one of the first andsecond annular coupling flanges, the annular radial segment defining anannular gasket abutment face; and an annular gasket including an annulargasket layer generally opposing and seated on the annular gasketabutment face, wherein the annular gasket layer includes a radiallyinner annular gasket segment and a radially outer annular gasket segmentsurrounding the radially inner annular gasket segment, wherein theradially inner annular gasket segment comprises a first materialsuitable for forming a liquid-tight seal with the annular gasketabutment face, wherein the radially outer annular gasket segmentcomprises a second material suitable for forming a fire-rated seal withthe annular gasket abutment face.
 17. The flange joint assembly setforth in claim 16, wherein the annular gasket layer comprises two of theannular gasket layers generally opposing one another.
 18. The flangejoint assembly set forth in claim 17, wherein the annular gasket furtherincludes an annular substrate sandwiched between the two annular gasketlayers.
 19. The flange joint assembly set forth in claim 18, wherein theannular substrate is corrugated radially.
 20. The flange joint assemblyset forth in claim 16, wherein the radially inner annular gasket segmentcomprises a fluoropolymer.
 21. The flange joint assembly set forth inclaim 20, wherein the radially inner annular gasket segment comprisesexpanded polytetrafluoroethylene (ePTFE).